expect: Improve report when matcher fails, part 12

[pedrottimark]

Summary

For .toThrow and .toThrowError matchers:

• Display not following expected label
• Inverse highlight not-expected substring or pattern in received error message
• Omit received error message for object instance because criterion is === strict equality

Residue

• Improve report for error class if received error.name is not the same as error.constructor.name probably together with .toBeInstanceOf matcher
• Breaking change to require .exec method in addition to .test method for RegExp

For more information, see discussion with @jeysal in #7795

Test plan

Change error message to more realistic "Invalid array length" in 6 .not snapshots

Chore in snapshot names:

• replace .toThrow() and .toThrowError() with toThrow and toThrowError
• replace strings with substring

Updated existing tests: all 60 names because of chore and snapshots:

expected
asymmetric	8
error-message	2
regexp	4
substring	4

See also pictures in following comment.

[pedrottimark]

Example pictures baseline at left and improved at right

error message includes the substring:

error message matches the pattern:

error message is equal to the message property of the object:

thrown value matches the asymmetric matcher:

[SimenB]

instanceof RegExp?

[pedrottimark]

Good question, as usual.

Some expect code tries to avoid instanceof but is it still a problem?

[SimenB]

I think that might be due to e.g. Error being weird across sandbox boundaries. But here we want you to pass something to us that we run.

I confused myself with that sentence 😛 Did it make sense?

[SimenB]

matcher error if not string or regexp? maybe next major

[pedrottimark]

A place to change in next major is in createMatcher function, replace:

    } else if (expected !== null && typeof expected.test === 'function') {
      return toThrowExpectedRegExp(matcherName, options, thrown, expected);

with

    } else if (expected instanceof RegExp) {
      return toThrowExpectedRegExp(matcherName, options, thrown, expected);

[jeysal]

nice work, LGTM 👍

[github-actions]

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